1. Field of the Invention
The present invention relates to a sealed container for holding therein liquid such as eye drops, cleaning solution for contact lens, the container having a container body with a liquid outlet thereof being factory-sealed for preventing or restricting contamination of the liquid by microorganisms or evaporation of the liquid before use, the liquid outlet being opened up to be communicated for use when penetrated in association with an operation of a cap.
2. Description of the Related Art
Containers of the above-noted type are known as follows (1)-(3).
(1) A container includes a container body storing liquid therein and having a factory-sealed liquid outlet and a cap detachably tightened on the container body. The cap forms, in its inner peripheral face, a female thread which is engageable with a male thread formed in an outer peripheral face of the container body. The cap also forms, in an inner bottom face thereof, a conical projection for penetrating the liquid outlet of the container body in association with a tightening (screwing) operation of the cap relative to the container body.
(2) A container includes a container body storing liquid therein and having a factory-sealed liquid outlet, a cap detachably tightened on the container body, a liquid discharge plug including a conical projection in the form of a needle capable of penetrating the liquid outlet of the container body and a discharge passage communicating between the inside and outside the container body through an inlet defined in an outer peripheral face of the projection, and a cap detachably fitted on the liquid discharge plug adjacent a peripheral edge of an exit of the discharge passage for sealing this discharge passage. The cap forms, in its inner peripheral face, a female thread which is engageable with a male thread formed in an outer peripheral face of the container body. In association with a tightening (screwing) operation of the cap relative to the container body, the conical projection of the liquid discharge plug is caused to advance for penetrating the sealed liquid outlet to allow discharge of the liquid for use (e.g. Japanese published utility model gazette No. 3-44686).
(3) A container includes a container body storing liquid therein and having a factory-sealed liquid outlet, a cap detachably tightened on the container body, a liquid discharge plug including a conical projection in the form of a needle capable of penetrating the liquid outlet of the container body and a discharge passage communicating between the inside and outside the container body through an inlet defined in an outer peripheral face of the projection, and a cap detachably fitted on the liquid discharge plug adjacent a peripheral edge of an exit of the discharge passage for sealing this discharge passage. The cap forms, in its inner peripheral face, a female thread which is engageable with a male thread formed in an outer peripheral face of the container body. In association with a tightening (screwing) operation of the cap relative to the container body, the conical projection of the liquid discharge plug is caused to advance for penetrating the sealed liquid outlet to allow discharge of the liquid for use. Further, at mutually opposing portions of the liquid discharge plug and the container body respectively, there is provided anti-withdrawal means for preventing loosening rotation of the liquid discharge plug when the liquid discharge plug has been tightened relative to the container body to a predetermined set position (e.g. Japanese utility model registration gazette No. 2560817).
In the case of (1), the factory-sealed liquid outlet is opened up by means of penetration thereof by the conical projection formed in the cap by utilizing the tighten-attachment operation of the cap on to the container body. Unless the cap is tightened properly to the predetermined set position relative to the container body, the amount of penetration of the projection into the liquid outlet of the container body will be insufficient, whereby a smaller aperture than desired will be formed in the liquid outlet, leading to difficulty in discharging operation of the liquid from the container body.
Similarly, in the cases of (2) and (3), the factory-sealed liquid outlet is opened up by means of penetration thereof by the conical projection formed in the liquid discharge plug by utilizing the screw-attachment operation of the plug on to the container body. Unless the plug is tightened properly to the predetermined set position relative to the container body, the amount of penetration of the projection into the liquid outlet of the container body will be insufficient, whereby a smaller aperture than desired will be formed in the liquid outlet, leading to difficulty in discharging operation of the liquid from the container body.
That is to say, in all of the conventional container constructions (1)-(3), unless the cap or plug is tightened or tightened properly to a predetermined set position on the container body, the container, when unsealed for use, will be unable to provide its full liquid discharging performance.
In addition, in all of (1)-(3), in order to prevent further tightening or tightening movement of the cap or plug relative to the container body once the former has reached the predetermined set position, the terminal end of the tightenable range of the cap or plug relative to the container body is set at the predetermined set position. However, for penetrating and opening up the liquid outlet of the container body, a significant force is needed. Then, if such great force is continuously applied after arrival of the cap or plug at the predetermined set position, the cap or plug will be forcibly tightened and twisted relative to the container body. As a result, one or both of the female thread of the container body and male thread of the cap or plug may be deformed or even broken.
Moreover, in the case of (1), in the course of the tightening operation of the cap relative to the container body, the cap is subjected to a significant reaction force from the penetrating operation into the liquid outlet of the container body, whereby the axis of the female thread of the cap tends to be inclined relative to the axis of the male thread of the container body. If the cap is forcibly advanced with such axial inclination to the predetermined set position, the orientation of the resultant aperture formed in the liquid outlet too will be inclined. As a result, the direction of liquid discharged from this unsealed container body will be different from a predetermined discharging direction.
With the constructions of (2) and (3), the liquid discharge plug is un-withdrawably retained at the predetermined set position of the container body with the projection of the former being kept penetrated into the liquid outlet of the latter. Therefore, communication between the inside of the container body and the outlet of the plug may be reliably maintained via the discharge passage formed in the projection or needle. Further, the discharging direction of the liquid from the container body may be restricted by means of the discharge passage and also the un-withdrawable attachment of the plug to the container body too may be effected easily with the series of operation steps described above.
However, if the container body, liquid discharge plug and the cap are to be shipped from the factory as separate components, the packing will be bulky. Further, before putting these into use, a troublesome assembly operation is needed on the side of the user, including the step of tightening the plug on the cap and the further step of attaching the cap to the plug. For this reason, it is desired to have the container body, plug and cap pre-assembled at the factory.
In this case, the liquid discharge plug will have to be temporarily, i.e. loosely tightened on the container body at a predetermined tightening position before the needle formed on the former is penetrated into the liquid outlet of the latter; and then the cap is attached to this plug. However, under such temporarily tightened condition, it is not readily possible to judge from the outside of the container whether the liquid outlet of the container body is unsealed or not. Moreover, with most of containers in general, the cap is to be turned in the loosening (unscrewing) direction for opening the container. Then, even if an instruction note is attached to the container, there is the possibility that the user, due to his/her carelessness or misunderstanding, may erroneously operate the liquid discharge plug (in the case of (2)) or the cap (in the case of (3)) in the opposite, i.e. loosening direction.
With such erroneous operation above, the plug and/or the cap may be detached from the container body. When the user first notices the error by finding the still sealed condition of the liquid outlet, he/she will have to re-attach the plug to the container body by a tightening operation. Then, the initial object of facilitating user's handling of the container will not be achieved. Also, if the user fails to notice the sealed condition of the outlet, he/she may try to open the outlet by means of a needle or similar tool prepared by him/herself; and if this needle or tool is not properly sterilized, the liquid outlet may be contaminated with microorganisms.
The present invention attends to the above-described states of the art, and its primary object is to provide an improved sealed container in which a factory-sealed liquid outlet of a container body can be unsealed in reliable, easy and unmistakable manner by means of penetration thereof by a needle provided to a liquid discharge plug with utilization of a loosening (unscrewing) operation of a cap without forcible tightening (screwing) operation thereof relative to the container body.